The present invention relates to the development of vital wheat gluten in non-aqueous media. The gluten which have been developed in such a way can easily be stored for a prolonged period of time under ambient storing conditions. The gluten are used in the preparation of chewable consumable products, they are also used in processed foods and feeds.
Conventional chewing gums have achieved a broad success in the marketplace. Such chewing gums are typically made of a gum base and a coating. Both of these parts further contain compounds, which act as sweeteners, colourants, flavours, preservatives and processing aids. Such ingredients also serve to modify the bite and taste of the product:
Conventional gum bases may be chosen from natural or synthetic resins such as chicle, natural rubber, guttapercha, lechi capsi, sorva, gunakay, crown gum, butadiene-styrene copolymers, polyisobutylene, isobutylene-isoprene copolymers, polyvinyl acetate, and polyvinyl alcohol. The gum base, which is water insoluble and chewable further comprises elastomers, resins, fats, oils, waxes, softeners and fillers. As a softener or plasticiser the following molecules can be used lanolin, propylene glycol, glycerine or triacetin in amounts of up to 10 weight %. Other additives include fillers and anti-sticking agents.
The products used as basic ingredient for the gum base are not biodegradable and do not degrade upon chewing either. This distinguishes the chewing gum from the chewy candies, which are completely digestible. Disposal of conventional chewing gum can cause unsightly litter.
Wheat gluten has been tried as a digestible and biodegradable alternative to the mentioned gum base ingredients. In addition to their being biodegradable when discarded the gluten, because they are proteins, are not harmful to the human body should they be swallowed. To the contrary, gums based on or including gluten would be nutritious.
U.S. Pat. No. 3,814,815 describes a method of manufacturing a gum base in which gluten are denatured by more than 10% and preferably between 10 and 60%. Denaturation is described to be performed in an excess of water either by heating or freezing. International patent application WO 95/12322 discloses the use of gluten as a gum base for chewing gum. In order to improve the chewability characteristics the gluten are cross-linked with a protein condensing agent, preferably tannin. It is recognized that the gluten-based chewing gums have a high moisture content, which renders the gums susceptible to microbial spoilage. In order to avoid this spoilage preservatives are added.
WO 94/17673 describes an improvement in the chew of gluten when used as a gum base wherein the improvement consists in the addition of a texturizing agent.
U.S. Pat. No. 3,692,535 relates to the preparation of ready-to-bake pie crust. The pie crust is said to be shelf stable without refrigeration and can be rolled or otherwise handled without crumbling or breaking. As indicated in the description (col.2, lines 3-21) the complete flour is developed in water. This necessitates the addition of preservatives to inhibit microbial growth.
U.S. Pat. No. 5,366,740 relates to the use of a combination of spray dried and flash dried gluten as a chewing gum base.
U.S. Pat. No. 5,665,152 relates to the forming of solid, non-edible biodegradable, grain protein-based articles.
U.S. Pat. No. 5,945,142 relates to the addition of small amounts of gluten to the norma chewing gum base in order to reduce the squeakiness.
Despite the fact that gluten have found acceptance in a wide range of applications gluten have to date not gained a reasonable markets share in food or feed applications. In the chewing gum field the use of gluten has been hampered by a number of organoleptic factors and no gluten based chewing gum has gained wide acceptance in the market, regardless of the advantages of degradability and edibility of the gluten.
In addition to the organoleptic factors one of the reasons therefore is the wide-spread belief that it is necessary to develop the gluten in an aqueous medium. Development in an aqueous medium results in the presence of too much water in the final product, which makes the product perishable due to the growth of microorganisms. The present invention solves this problem.
An object of the present invention is to produce a digestible, degradable gluten basic composition, which can be stored for a prolonged period of time without degradation and which can be used as a gum base for chewing gums, chewable candies, and process food or feed. The storage conditions are the normal storage conditions for gluten.
The present invention discloses a developed vital wheat gluten wherein the development was performed in a non-aqueous medium i.e. a medium having a Aw of less then 0.8, or with a Aw so that the final composition has a Aw less than 0.7.
A preferred medium for developing the gluten is a concentrated carbohydrate solution, containing less than 30% of water, preferably less than 20%, more preferably less than 10% (w/w).
The present invention also discloses a method for developing wheat gluten in a non-aqueous medium. The method comprises the steps of
mixing gluten 20-60% (d.s. w/w) with a non-aqueous medium,
kneading the mixture at a temperature of between 50 and 90xc2x0C.,
continuing the kneading until the value of at least 75% of the maximal torque is reached,
shaping the gluten into a desired form.
The present invention further discloses the use of the so-developed wheat gluten as a gum base for chewing gums, or as basis for chewing candies.
Wheat gluten developed in non-aqueous media has been applied in food applications but also in bakery and processed food. The wheat gluten was further applied in feed applications such as in pet food or fish feed.